One older in office, or whose entrance upon office was anterior to that of another; one prior in grade.

3.

An aged person; an older.

Dryden.

Each village senior paused to scan,
And speak the lovely caravan.
Emerson.

4.

One in the fourth or final year of his collegiate course at an American college; -- originally called senior sophister; also, one in the last year of the course at a professional schools or at a seminary.